New Glass Technique

I was attempting to explain a glassing process that I have been using for a number of years now to a friend and realized that not many fabricators are using it (at least to my knowledge). So I thought I would share here and see if anyone has any twists to add to it. I start with an MDF skeleton (nothing new here). I then wrap a thin cardboard (known as "chipboard" in the upholstery industry) around the parts that I want to glass. My favorite part of doing it this way is that there is vert little glass and filler to be done on the surface. The back of the chipboard can be reinforced if need be. Complex shapes that would normally require expensive and time consuming foam can be made this way. I have found that if you rabbit a grove into the edge of the MDF for the chipboard to sit in you get a nice smooth transition that will need very little effort to glass over seamlessly. Notice the black fiberglass showing through the green body filler (I use black glass). This is due to the surface being so close to perfect that only a thin layer of filler is required. I would like thoughts and ideas but if you are a DIY or experimenter please don't pass off opinions as fact. I appreciate all input from creditable sources and all questions or ideas from anyone. Thanks.

speakermakers do you build up the FG areas of the chipboard for the boxs where it is a wall of the box area? Only asking cause if the FG is thin then you get cracking and alot of flex from the pressure of sub. Your work is very nice!!!!!! And from your pics, you have given me new ideas with the chipboard to make a AMP rack in my truck. Thx by the way... what thickness is the chipboard and where can i get some?The best tool in my work shop, is my BRAIN!!!!

When you ask for chip board at an upholstery shop or upholstery supply they will generally give you three options: waterproof board (black 3/16" treated cardboard that is used to make door panels on classic cars), and two thicknesses of true chip board (thick and thin. I keep both thicknesses of chip board in stock at all times but use the thinner of the two the most. I don't use the black water proof board at all. Chip board sells for $1.50 or less a sheet. All areas that I use chip board on are then covered in aluminum foil, waxed, and then glassed over with "fatmat". I then remove the entire sandwich, peel off the chip board and aluminum, and bond the new fiberglass piece back in. When I am done the structure is strong enough to support a Mack truck. I am quite particular about how strong my glass work is. :) You will notice the cross pattern on the surface of my glass work. This is because I use a well thought out series of glass grades, layers & application to achieve a high strength to weight ratio as well as dimensional stability. I am a big believer in over building everything, though my techniques allow my final glass areas to be much denser, stronger, and thinner than you will typically see. Thanks for the complements!

definitely gives me some ideas too. ill have to see if they carry that stuff at the upholstery distributor i get my headliner and vinyl material from. im planning a glass box in my truck for my up-coming RE XXX12 and space is at a premium so ill be using a decent amount of glass. i have a technique that you might be able to use to fill in some finer detail in your overall shapes with fiberglass using modeling clay as a surface that you can sculpt complex shapes and then glass over without having the clay stick to the glass. you can also take a physical object and press it into the clay to get a mold and then glass into the mold to make a fiberglass replica. this is good for logos and badges that are too small or complicated to make out of wood. you can also fill the mold with some sort of clear resin then paint it and light it up from underneath. im far from an expert with fiberglass so i havent used this idea much at all but i dont see how it could fail for making small parts.

I'm interested. Post some pics please.

sorry i havent actually made anything with this technique yet but i will be using it in the next few weeks. im building a fiberglass box for a 12 inch RE XXX and im going to make the "XXX" logo out of pure resin and mold it into a panel and have it back-lit. it will be painted probably black but it will still glow when the lights are off. ive gone through it a thousand times in my head and i honestly dont see how anything can go wrong. ill definitely post pics and a tutorial when im done.

So you are glassing over the chipboard, using it as a form basically? then removing the chipboard and bonding back in the glass piece?Gary Sather

Sorry. and what do you mean glassed over with fatmat. fatmat is a peel and stick sound deaden-er like dynamat, not fiberglass.Gary Sather

Also for application where you need more fiberglass than wood for lighter weight etc a technique I've used is making a wood frame using 1x2 and mdf rings for the subs. I will wrap the frame in thick trunk liner thick carped. Non backed. So essentially all it is is a carpeted frame. Then I use resin mixed with bondo for extra strength and glass the carpet. Which gives me one solig glassed box that is extremely strong and light for the size but still fairly heavy considering. Over all thickness of the glass ends up being about 1/3" thick. And extra strong. I ususlly dynamat the inside and it helps it sound acoustically more like a wood box with all the strngth but less weight and is a fast process. This was one of those boxes that ended wrapped in suede.   I have photos of the process I can also post.Gary Sather

the glassed carpet box is strong but a properly layered fiberglass box will be stronger because of the fabric direction. if you alternate the directions through each layer you will end up with something extremely strong. the carpet will have air in it too because theres no way to really push the air out, all you can do is saturate it as best as you can but air will still be there in some spots, its just too thick. nothing against you personally, that box and amp rack does look pretty nice but its probably not as strong as you think. did you cover it with suede?